Content updates do not affect any items already embedded in project files, these would need to be removed from the scene and replaced with the updated item. Replace or leave as is depends on just what has been changed in the item and if the changes are significant enough to justify the replacement. Some items, such as Morphs already baked are impossible to replace while those that have been heavily modified by the user in the scene may involve too much work to replace.
I assume however that anything being offered for sale would have to be replaced while items rendered in a video scene may be OK as they are.
Gerry
System: Win 10 Pro (21H2), Asus X99-E WS, CPU i7-5930K -3,5 GHz, 32 GB DDR4 2666-16 RAM, NVidia GTX 1080 Ti GPU - 11 GB VRAM(Driver Studio-536.99), Samsung 850 Pro 512 GB SSD, 6 TB HD storage.